Constipation, Diarrhea, and GERD Flashcards Preview

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Flashcards in Constipation, Diarrhea, and GERD Deck (145)
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What are the Rome III criteria for functional constipation?

at least two of the following for the last 3 months with onset in the prior 6 months: straining (25% of BMs), lumpy or hard stool (Bristol Stool Scale Form 1 or 2 - 25% of BMs), sensation of incomplete evacuation (25% of BMs), manual maneuvers (25% of BMs), sensation of obstruction (25% of BMs), < 3 BMs/week; loose stools rarely present without laxatives; insufficient criteria for IBS


What is stercoral ulceration?

ulcer of the colon due to pressure and irritation resulting from severe, prolonged constipation due to large bowel obstruction (commonly located in the rectum)


What is the puborectalis muscle?

muscle that contributes towards the maintenance of fecal continence - loops around the rectum like a sling, pulling the rectum forward to create a more acute angle between the rectum and the anal canal => squatting fully relaxes the muscle and allows for easier defecation


What are the three types of primary colorectal dysfunction?

(1) slow transit constipation - delay throughout the colon (dysfunction of colonic smooth muscle or neuronal innervation and obstruction); (2) dyssynergic defecation - difficulty expelling stool from the anorectum; (3) IBS predominant constipation (abdominal pain and altered bowel habits)


What are common causes of secondary constipation?

endocrine/metabolic disorders, neurologic disorders, myogenic disorders, medications (opioids), psychiatric disorders (anorexia nervosa), chronic idiopathic constipation (no physiological abnormality)


What are some neurogenic disorders associated with chronic constipation?

DM, Hirschsprung disease (absence of ganglion cells), Chagas disease (disease of the nervous system that can cause megacolon and chronic constipation), MS, spinal cord injury


What are some non-neurogenic disorders associated with chronic constipation?

hypothyroidism, hypokalemia, anorexia nervosa, pregnancy


Which receptor is associated with opioid-induced chronic constipation?

mu-opioid receptors in the GI tract - opioids bind to these receptors, leading to inhibition of the propulsive activity of the intestine and slowing intestinal transit


Which drugs are commonly associated with constipation?

opiates, antihypertensives, CCBs, iron supplements, aluminum, analgesics, antihistamines, antispasmodics, antidepressants, antipsychotics, serotonin (5-HT3) receptor antagonists (block the vomiting reflex - ondansetron)


What are red flags associated with constipation?

hematochezia (passage of fresh blood through the anus), + fecal occult blood test, obstructive symptoms, acute onset constipation, severe constipation unresponsive to Tx, weight loss > 10 pounds, change in stool caliber, family Hx of colon cancer/IBD


What other factors can contribute to constipation?

immobility, chronic medical problems (pain, DM), psychosocial problems (isolation, poor nutrition)


How should you conduct an exam for constipation?

thorough Hx, rectal exam, and bowel diary => reserve other diagnostic studies for selected individuals


What are the treatments for constipation?

(1) lifestyle and dietary modification, (2) bulk laxatives (psyllium [Metamucil], polycarbophil [FiberCon], wheat dextriumn [Benefiber], methylcellulose [Citrucel]), (3) osmotic laxatives - contain polyethylene glycol (GoLYTELY, GlycoLax, and MiraLax), (4) colon secretagogues (lubiprostone), (5) enemas (only to prevent fecal impaction in PTs with several days of constipation)


What is the mechanism of action of osmotic laxatives (polyethylene glycol - GoLYTELY [electrolyte] and MiraLAX [powdered])?

hold water in the stool to soften the stool and increase the number of bowel movements - improves stool frequency and consistency => start with 17 g powder dissolved in 8 oz of water daily and titrate up/down to effect


What is the mechanism of action of bulk forming laxatives (psyllium seed/Metamucil, methylcellulose/Citrucel, calcium polycarbophil/FiberCon, wheat dextrin/Benefiber)?

natural or synthetic polysaccharides or cellulose derivatives - are not digested but absorb liquid in the intestines and swell to form a soft, bulky stool


What is pelvic floor dyssynergia/functional outlet disorder?

condition in which the external anal sphincter and the puborectalis muscle contract rather than relax during an attempted bowel movement - there is the sensation of incomplete emptying of the rectum; Dx made via manometry and balloon expulsion test => may be treated with biofeedback


What are the recommendations for establishing a regular pattern of bowel movement?

attempt to empty the bowel at the same time every day - within 2 hours of waking and within the first 30 minutes after a meal (to take advantage of postprandial increases in colonic motility); attempt a BM at least twice per day; strain no more than 5 minutes


What dietary changes are recommended to treat constipation?

increase fluid and fiber intake - fiber intake of 20-25 g/day


What are some types of natural laxatives that may be safe to use with constipation?

flaxseed, psyllium fiber, triphala (composed of 3 fruits common to the Indian subcontinent: Amalaki [Emblica officinalis], Bibhitaki [Terminalia belerica] and Haritaki [Terminalia chebula])


What is anorectal manometry?

a small, flexible sensor is placed in the rectum and connected to a computer with a recording device that measures the pressure and strength of the anal and rectal muscles - the patient is asked to perform certain maneuvers such as squeezing, relaxing, or pushing as if to pass stool - abnormal finding suggests a defecatory disorder


What is the balloon expulsion test?

PT is placed in a left lateral decubitus position with flexion of the knees and hips - a well lubricated empty balloon is gently inserted into the rectum and the balloon is inflated by a fixed volume (typically 50 mL of water or until the patients feel a desire to defecate) => PT is then asked to attempt to evacuate the balloon in the sitting position in privacy - abnormal finding suggests a defactory disorder


Which laboratory tests should be ordered in PTs with constipation?

complete metabolic panel (serum glucose, creatinine, calcium), CBC with differential, thyroid function tests


Which patients should receive laboratory testing with constipation?

PTs with hematochezia, weigh loss > 10 lbs., family Hx of colon cancer or IBD, anemia, positive fecal occult blood test


Which patients should receive diagnostic colonoscopy with constipation?

age < 50 years who have not previously had colon cancer screening, constipation with alarm features, prior to surgery for constipation


Which PTs should receive radiographic studies for constipation?

suspected megacolon and barium radiograph in PTs with suspected Hirschsprung disease


Which PTs should receive assessment with colon transit study for constipation?

those with infrequent defecation - used with radiopaque markers or wireless motility capsule


What is colonic transit time?

time it takes for stool to pass through the colon


What is defecography?

imaging study which provides information about anatomical and functional changes of the anorectum - most useful in examining anatomic causes of constipation - performed by placing 150 mL of barium into the PT's rectum and having PT squeeze, cough, or bear down


How is dyssynergia diagnosed on defecography?

presence of insufficient descent of the perineum (< 1 cm) and less than a normal change in the anorectal angle (< 15 degrees)


How is defecatory dysfunction managed?

suppositories (glycerin or biscodyl - liquify stool), biofeedback (used to correct inappropriate contraction of the pelvic floor muscles and external anal sphincter), or botulinum toxin injections into the puborectalis muscle (60-100 U into both sides of the muscle)